WR7 days


i started using nr7 and nr4 inside days a few months ago as a heads up that a trend day may follow. I haven't read crabel's book so am not very knowledgeable on his ideas. I'm wondering if anyone can shed light on WR7 - is WR7 just a heads up that a NR day may follow , or is there more to it ?
I believe that the WR's were originally (or still are) called WS's - Wide Spreads - and not Wide Ranges. So Crabel tracked the same WS's as he did NR's: WS, WS4, WS5, WS7. I don't believe that he found as much predictive power in the WS's as he found in the NR's and that is why people don't refer to them as much. Although I've read his book I don't recall exactly what he was looking for after a WS. It's been a while since I last read it.